The present invention relates to an amusement ride, such as a roller coaster, comprising a vehicle track configured for guiding a passenger vehicle along that vehicle track. More in particular, the invention relates to a booster drive for displacing a vehicle along the vehicle track of an amusement ride.
Amusement rides, such as coaster rides, are known in the art. They comprise a rail type vehicle track that defines a support surface for supporting a passenger vehicle, and that guides the passenger vehicle along that vehicle track. The vehicle track is designed to provide passengers with a thrill by guiding the passenger vehicles at high speeds along a curved vehicle track. Thrills are for example achieved by providing the track with steep drops, high-speed turns, loopings, etc.
The passenger vehicles of this type of amusement rides typically are not self powered vehicles. Traditionally, a lift hill is provided at the beginning of the track. The passenger vehicle is pulled onto the lift hill and is subsequently propelled down the lift hill by gravity, thus obtaining a speed sufficient to complete the track.
In more recent designs, booster drives have been provided along the track to provide the passenger vehicles with additional speed while traveling along the track. The booster drives are provided with booster wheels configured to engage a longitudinal drive fin provided at the bottom side of the passenger vehicles, and to propel that drive fin, and thus the passenger vehicle, along the track. The booster drives are mounted along the track such that the drive fin of a passing passenger vehicle is engaged by the booster wheels, more in particular is pinched between the booster wheels, each wheel engaging one of the contact surfaces of the drive fin.
The drive fin is a longitudinal beam or plate that is provided at the underside of the passenger vehicle. The drive fin is on opposite sides provided with contact surfaces. It extends in the direction of travel, typically the longitudinal direction, of the vehicle. To enable the booster drives to propel the passenger vehicle forward, a drive fin of considerable length and stiffness is needed.
The booster drives have two booster wheels that are positioned to pinch the drive fin of a passing vehicle between them. By driving one or both of the wheels, the booster drive pushes the drive fin in the direction of travel of the vehicle, and thus propels the passenger vehicle further along the track. Providing booster drives along the track thus enables to propel passenger vehicles while traveling along the track. Therefore, the lift hill at the beginning of the track can be reduced in size and/or the track can be extended. Furthermore, by using booster drives increased speeds can be achieved along the track.
With the known booster drives, speed control along the track is however still limited. To correctly engage the drive fin, the booster drives need to be exactly positioned in the track. Furthermore, to correctly propel the drive fin along the track, the booster wheels need to stay correctly positioned relative to the drive fin of the passing vehicle. If only one of the booster wheels engages the drive fin, insufficient force can be transferred from the booster drive to the vehicle. Typically, the drive fin is located at the center of the vehicle and the booster drives are provided at the center of the track. Because the drive fin is a long and straight element, it will not follow the curvature of a track. Thus, when the vehicle travels along a curved section of the track, the position of the drive fin relative to a booster drive fixed at the center of the track will change, which prevents the booster wheels from a constant engagement with the drive fin. Therefore, the use of booster drives is restricted to straight sections of the roller coaster track. This limits the control over the speed of the vehicle along the vehicle track, which typically comprises many curved sections, and thus limits the level of thrill that can be provided to the passengers of the vehicle.
In U.S. Pat. No. 4,361,094 it has been suggested to provide the passenger vehicles of coaster type rides with a flexible drive fin. By allowing the drive fin to move in a lateral direction, the position of the booster drives relative to the track is less critical. Furthermore, the flexible drive fin allows for booster drives to be located along curved sections of the vehicle track. However, a drawback of the disclosed flexible drive fin is that its flexibility does not allow for optimal transfer of the drive force between booster and passenger vehicle.
It is an object of the present invention to provide an alternative amusement ride, more in particular to provide an amusement ride with improved booster drives. Another object of the invention is to provide an improved booster drive for use in such amusement rides. Another object is to provide a booster drive that can be used with traditional drive fins along straight as well as curved trajectories of a track.